Aimin Jiang Hon Keung Kwan IIR Digital Filter Design with Novel Stability Criterion Based on Argument Principle. 2339-2342 2007 conf/iscas/2007 ISCAS http://doi.ieeecomputersociety.org/10.1109/ISCAS.2007.378857 db/conf/iscas/iscas2007.html#JiangK07